Module 2: proteins Flashcards
Draw the general structure of an amino acid
Yuh
Describe how a dipeptide is formed from two amino acids
Condensation reaction.
The OH of the carboxyl acid group in one amino acid bonds with a H atom from the amino group of the other amino acid.
This produces water.
Forms a peptide bond.
Define the term primary structure
The sequence of amino acids in a polypeptide chain
Describe how the secondary structure of a protein is formed
The polypeptide chains coil to form alpha helixes
Or fold to form beta pleated sheets
Describe how the tertiary structure of a protein is formed (include details of the different bonds that old the protein in its tertiary structure)
The alpha helixes and beta pleated sheets coil and fold further.
Held in place by lots of bonds.
Ionic bonds between amino aids of opposite charge.
Hydrogen bonds between amino acids with slight charges.
Disulfide bonds that form between sulfur atoms in two cysteine amino acids.
Hydrophilic interactions - hydrophilic amino acids are found on the outside of the protein.
Describe two examples of where the tertiary structure of a protein is crucial to its function.
- Enzymes: Shape of active site of specific
And complementary to the substrate.
If the tertiary shape is altered, the enzyme can’t hydrolyse the substrate. - Hormones: Shape is specific
And complementary to the receptor.
If the tertiary shape is altered, the hormone won’t combine with the receptor.
Define the term quaternary structure.
A protein made up of different polypeptide chains.
Define the term conjugated protein.
A protein with a non-protein group attached.
The non-protein group is called a prosthetic group.
Describe the general structure of a globular protein.
Spherical.
Amino acids with hydrophilic R groups are on the outside.
Souble.
Describe the structure of haemoglobin
Four polypeptide chains.
Each polypeptide chain has a haem group as a prosthetic group.
Each haem group contains iron.
